- Written by Jim Clements
- Published on 02 January 2014
Setup of the REL T-9 Subwoofer
I evaluated the REL T-9 concurrently with my recent review of the Sonus faber Venere 3.0 surround system. This system included a pair of Sonus faber Venere 3.0 floorstanders, the Venere Center and a pair of Venere Walls along with the REL T-9 for a complete 5.1-channel set up.
I placed the REL T-9 in the front left corner of the room and started out by connecting the mono sub output of my surround processor to the low level input on the REL plate amp. I was going to use my processor's built-in bass management as one would do with most any other subwoofer. So I set the sub's crossover to the max frequency (120 Hz) and set the volume to half mast. Meanwhile, the Venere 3.0's have useable in-room response down to about 34 Hz which means that I could set the crossover as low as 40 Hz in my processor if I wanted. I started with 40 Hz and even tried 60 Hz and 80 Hz while setting the level in the surround processor as well.
I generally liked what I heard, but the sound just wasn't gelling the way I wanted. The bass was in balance but felt just a little bit disconnected for my tastes (a very common problem with most subs). That is when I decided to try the REL T-9 via its included High Level hook up cable. This cable connects in parallel to the speaker outputs on your amp and is terminated at the sub's plate amp by way of a Neutrik Speakon connector. The input impedance to the sub is very high so its presence in the circuit doesn't affect the signal going to your main speakers in any way.
In this case you set your mains to "large", tell your processor you do not have a sub, then manually dial in a crossover and level setting on the sub's amp to get the best blend. Since the crossover is controlled by an analog dial with limited graduations on the scale, I was not sure of the final crossover setting, but it was somewhere between 50 – 60 Hz. Of course, this would mean "double bass", but in practice this connection scenario was by far the best sound I got from the system.
At the time of review, I was driving the main speakers with a Krell s550i integrated amp set to theater bypass. This amplifier is fully balanced architecture and so I grounded the high level connector to the chassis as per the REL manual.
The REL can also be connected via the .1 LFE low level input at the same time. This input has its own level knob. In this configuration, the discrete LFE signal will be reproduced by the sub. The LFE spec includes frequencies up to 120 Hz and this theoretically would be less taxing on your main speakers. I tried this set up for a few days but decided that I liked the single high level connection better.
The main point of the foregoing narrative is to say that the high level hook up far surpassed what I heard from the typical low level connection. I am at a loss to fully explain why this is, but what I heard was indisputable. It was a vast improvement. The bass was better connected to the rest of the audible band and the blend at the crossover frequency was nearly seamless. As with other high quality subs, I was then able to increase the sub's level for greater impact while the sound of the bass remained as a whole with the rest of the music.